Manufacture of sulfocyanids.



K. M; CHAN-0E.

MANUFACTURE OF smrocmmns.

APPLICATION I'ILBD JAN. 6, 1909.

9 5 Patented May 25, 1909.

Wibwaswl WET were KENNETH MACOMB CHAN OE, OF LONDON, ENGLAND, ASSIGNOR TO THE BRITISH OYANIDES COMPANY, LIMITED, OF LONDON, ENGLAND.

MANUFACTURE or snnrocranins.

Cyanids, of which the following is a-spec'i-f fication. p

The United States Patent No. 705,152, of

July 22, 1902, describes the extraction of cyanogen from coal gas by scrubbing the gas with ammoniacal or gas liquor or water and sulfur.

In carrying out the invention descr bed 1n that. patent it has hitherto been deemed necessary to scrub the gas in a'costly and complic ted scrubber of the type commonly used for-extracting ammonia from coalgas. I

have found that such scrubbers besides involving considerable initial outlay are costly to maintain-1n good working order because the complicated revolving apparatus of such scrubbers are, when sulfur is employed, liable to great wear and tear and to break down with consequent stoppage of the working of the plant. I

I have found that in working with gas: from which the tar has already been indns trially extracted there generally remains sufticient tar to form a coating upon the sulfur which is being agitated in presenceof the gas containing cyanogen and this tar coating impedes the effective formation of polysulfids and consequentlythe subsequent formation of sulfocya'ni'ds. I have also found that in some gas works where the tar is pres ent in still greater quantity the effective working of the scrubbing apparatus is liable to b'e greatly impeded and even stopped by the tar in question. Hence it is very desirable to remove as far as possible the last traces of tar from the gas previous to passing it through liquor in which sulfur is'bein'g agitated.

The accompanying drawing is a vertical section showing an apparatus for the purification of coal gas.

a is the inlet through which the gas is brought to the chamber 1) from which a number of pipes 0 with serrated or perforated ends deliver it beneath the surface of the liquor contained in the first tank cl from which it passes by the pipe e to the chamber Specification of Letters Patent. Application filed January 6, 1909.v Serial No. 470,909. 7

Batent ed May 25, 1909.

f from which again a number of pipes 9- de liver it beneath the surface ofthe liquor in the second tank 72. in which is a stirrer i.

j is the exit pipe and 7a is a hopper by means of which sulfur and liquor may be introduced into the tank It.

- From the tank ha pipe Z leads to a vessel m in which is a downflow pipe at leading to the tank (1. The height of this pipe can be adjusted so as to regulate the rate of flow from-the tank h to the tank 03, such flow being due to the condensation from the gasjor to the addition of fresh liquor;

0 is a pipe putting the vessel m into co'mmunication with the tank It above the level of the liquor so as. to equalize the pressures. similar arrangement p may be used for the overflow of the liquor from the lower tank.

By the present arrangement of apparatus such removal is effectively brought about.

I first wash the gas in a liquor in which thereis no free sulfur but which contains alkaline polysulfid in solution and'next in ammoniacal or gas liquor or watertogether with free sulfur which is kept. agitated by means of some simple stirring appliance.

In the first washing as above indicated the" alkaline polysulfid reacts upon some of the cyanogen in the gas to form sulfocyanid. The sulfureted hydrogen thereby liberated passes with the gas to the second washing compartment containing the sulfur where the sulfureted hydrogen combines with the ammonia and the sulfur to form ammonium polysulfid which removes the remainder of the cyanogen while some of the polysulfid is in course led to the first vessel for use therein as above explained. v

If it be considered desirable to employ this washing apparatus for the production of sulfocyanids after instead of before the ammonia has been completely extracted from the gas it will then be necessary to introduce an alkaline base together with the sulfur.

While I wish to broadly-claim this process I for the simplified production of'sulfocyanids from gas no matter What the particular form of apparatus adopted I have described an apparatus by the aid of which the process may be cheaply and effectively carried out.

What I claim is 1. In the manufacture of sulfocyanidfrom gas, bringing the gas into intimate contact firstly with liquor containing a polysulfi-d and secondly with liquor which Contains sulfur and is kept in agitation substantially as described.

1n the manufacture of sulfocyanid from gas, bringing the gas into intimate contact firstly with liquor containing ammonium polysulfid and secondly with liquor which contains sulfur and is kept in agitation vsubstantially as described.

10 In the manufacture of sulfocyanid l ;sulfid-and secondly wi th'liquor which contains sulfur and an alkaline base and is kept in agitation substantially as described.

KENNETH MACOMB CHANCE.

Witnesses:

H. D. JAMESON, R. F. WILLIAMS. 

